An associate of a notorious international biker gang attacked a Corrections officer with a sharpened toothbrush at a Waikato prison on Friday.
The man, a remand prisoner in his early 20s, cannot be named for legal reasons but is understood to be a Mongols associate.
Corrections officers at Spring Hill prison in Te Kauwhata were preparing to unlock the man for recreation time when he attacked one staff member while still handcuffed, prison director Scott Walker said.
The Herald understands he went to stab the staffer with a sharpened plastic toothbrush handle, a commonly used improvised weapon in prisons.
Walker said officers quickly restrained the man and moved him to a management unit.
"Staff did an exceptional job to quickly resolve the incident and support their colleague."
The officer involved received a cut to the neck but was not seriously injured, he said.
The inmate received an internal misconduct charge and is in segregation after the assault.
Police are investigating but are yet to charge him.
"No assault on staff will be tolerated," Walker said.
"The impact that assaults have on our staff and the worry that then creates for their family and their colleagues cannot be downplayed."
The Mongols MC have been dubbed the most violent and dangerous motorcycle gang in the United States.
They have chapters in more than 10 countries and in recent years gained a foothold in New Zealand following the arrival in 2018 of a 501 deportee who was a member in Australia.
Tensions erupted into a series of tit-for-tat shootings and an arson between the Mongrel Mob and Mongols in the Bay of Plenty early in 2020.
Later that year the police National Organised Crime Group raided homes linked to Mongols members and associates across the region.